Question

Win 10, 64 bit, i5-6200u @ 2.3GHz, 8GB memory.   No other problems running Studio One.

Answer 1

I located a similar problem and tried that solution, and it worked.  as follows:

"... open Studio One and go to Studio One>Options(Preferences on Mac)>Advanced>Services and disable the VST2.4, VST3, or AU service that you might be using for your plug-in.  You can then open the problematic song and remove all instances of the plug-in."

This allowed me to remove the FX bus.